Two former Parramatta Eels players are accused of harbouring semi-automatic weapons and possessing more than half-a-million dollars in cash after dramatic arrests in Sydney's Centennial Park yesterday.

WA Labor, Libs match meth dealer penalties

Tough penalties for methamphetamine dealers are proving a central theme in the WA election campaign, with the major parties backing and matching each other's plans.

The opposition has focused on maximum sentences and targeting wholesalers rather than street dealers, promising life for 28 grams or more.

The Liberals have gone hard on minimum sentences, pledging to jail anyone caught dealing even small quantities of the drug.

Police will have discretion to determine whether someone found with just 1g is a dealer or not, looking at factors such as whether it had been divided up into bags or the offender had scales for weighing the drug.

Police Minister Liza Harvey also says they Libs will match Labor in lifting the maximum sentence from 25 years to life.

Under the Liberal plan, mandatory time behind bars would start at one year, rising to a minimum of 15 years for more than 200 grams.

"Anybody who is dealing in quantities of meth deserves to be behind bars," Ms Harvey told reporters.

Judges would not be happy, given mandatory sentencing removes their discretion, Attorney-General Michael Mischin conceded.

Surprisingly, opposition leader Mark McGowan said he supported the Liberal plan, which Labor would also implement.

"I'm fine with the policy but what I would say to the government is it's too little, it's too late," Mr McGowan said.

"They've had eight-and-a-half years."

Labor doesn't often support mandatory sentencing.

During the 2015 Canning by-election, it was a key differentiation between the meth policies of Liberal Andrew Hastie and Labor's Matt Keogh.

Mr Keogh, an experienced lawyer who later won the neighbouring seat of Burt, said he was strongly opposed to forcing set penalties on the judiciary.

What's certain is law and order will continue to raise its head during the 2017 campaign.

Ms Harvey said the proposed legislation announced on Sunday would be the top priority of a third-term Barnett government.

Mr McGowan also flagged a tougher approach to other serious offenders along with softer punishments for fine defaulters, who he doesn't believe should be jailed.

"We're going to ensure that our prisons are used more appropriately and people who commit serious crimes - dangerous sex offenders, drug dealers, domestic violence perpetrators - are in prison for longer," he said.